The world congress on justice, governance and law for environmental sustainabilty, which took place June 17-20 under the sponsorship of the UN environment programme, held both its opening and concluding sessions in the magnificent setting of Rio de Janeiro's Tribunal de Justiça. Chief justices, heads of jurisdiction, attorneys general, chief prosecutors, and other high-ranking representatives of the judicial, legal and auditing professions have been present in Rio over the last few days with the object of feeding their own recommendations into the work of the Rio+20 conference on sustainable development now taking place at heads of state and heads of government level.

The Bible speaks of "deep calling unto deep". Well here, over the last few days, it has been "summit calling to summit". On the first day we heard some moving statements by their supreme honours, if that is the right way to address the world's chief justices. Ricardo Luis Lorenzetti, president of Argentina's supreme court, told the august gathering that it was the duty of the judiciary to stop the politicians reneging on their promises. "The key role of the judiciary is that we do not depend on election" he said.

For the next three days participants repaired to a luxurious seaside hotel at Mangaratiba about 100 miles south of Rio. There, amid the sound of waving palm trees and the lapping oceans, they sat down to work out exactly what message it was they wanted to convey to the world's political leaders.

The UK's own supreme court was represented by Lord Carnwarth. Supreme court justices are on the whole modest men. Supremely modest, no doubt. Such a one is Lord Carnwarth. He would the last to claim that he exercised any influence over the deliberations which took place in the Portobello Resort.

Yet this reporter can testify to the fact that Lord Carnwath's subtle chairing of one of the world congress's key sessions led to possibly the congress's most important recommendation, namely that it was time to strengthen public participation in decision-making, and also to improve access to justice and information. The session considered the vital role of the judiciary (including public prosecutors and auditors) in the implementation and enforcement of environmental law.

Back in Rio's Tribunal de Justiça, Achim Steiner, Unep's executive director, had stressed on the opening day that: "Citizens have to be able to take their own governments to account for failure to uphold commitments they have entered into". Sitting as one of Lord Carnwath's panelists that morning in the Portobello resort, Syeed Mansoor Ali Shah, one of Pakistan's high court justices, confimed that his court had established rules under which the court would accept complaints and petitions "even if they are written on a grubby postcard in half-formed letters''.

Of course, there was controversy, even in that luscious environment. You can't put 100 lawyers in a room together and not expect some controversy. One bone of contention was whether or not to mention the question of ecocide. Louise Kulbicki, an invited participant from Legal Outreach, an organisation dedicated to "eradicating ecocide" argued passionately – and not without support – that the congress should urge the UN to add ecocide to its list of heinous crimes. She even read out a perfect plausible definition of ecocide to the gathering.

Kublicki later protested that her point of view had been ignored in the congress's final declaration. There will in due course be a full report of the congress's deliberations published by the UN. If Kublicki finds there is still no record of her interventions, she will no doubt know where to send her postcard.